An overview of charging environments

A brief synopsis of the natural environments that play a role in spacecraft charging is presented. Environments that cause both surface and internal charging are discussed along with the mechanisms involved. The geosynchronous and low altitude regions of the Earth's magnetosphere/ionosphere are considered and simple descriptions of each environment presented. As material properties are critical to the charging process, definition of material properties important to charging, which can be affected by the environment, are also described. Several space experiments are proposed that would help fill the gaps in the knowledge of the performance of materials in a charging environment

Macroscopic Observables Detecting Genuine Multipartite Entanglement and Partial Inseparability in Many-Body Systems

We show a general approach for detecting genuine multipartite entanglement (GME) and partial inseparability in many-body-systems by means of macroscopic observables (such as the energy) only. We show that the obtained criteria, the "GME gap" and "the k-entanglement gap", detect large areas of genuine multipartite entanglement and partial entanglement in typical many body states, which are not detected by other criteria. As genuine multipartite entanglement is a necessary property for several quantum information theoretic applications such as e.g. secret sharing or certain kinds of quantum computation, our methods can be used to select or design appropriate condensed matter systems.Comment: 4 pages, 3 figures, published version, title extende

Sentence imitation as a tool in identifying expressive morphosyntactic difficulties in children with severe speech difficulties

Background: Sentence imitation has been identified as a good indicator of children's language skills, with performance differentiating children with specific language impairment and showing relationships with other language measures. It has a number of advantages over other methods of assessment. The assessment of morphosyntax in children who have severe speech difficulties presents unique challenges which currently available sentence imitation assessments do not address. Aims: This paper presents a new sentence imitation test (The Sentence Imitation Test (SIT-61)) and reports on an investigation which sets out to determine whether this test (1) reveals differences in performance between a group of children diagnosed with specific language impairment and a group of typically developing children (2) reveals distinct profiles of performance amongst children with different speech difficulties, and (3) provides information about morphosyntactic strengths and difficulties. Methods & Procedures: SIT-61 is a finely graded sentence imitation test in which the phonotactic structure, segmental phonology and length of words were kept as developmentally simple as possible. Responses are scored for number of content words, function words and inflections correct. A novel scoring system was devised to credit a child where there was evidence of targeting a morpheme even if it was mispronounced. The test was administered to four groups of children between the ages of 4 and 6 years: 33 children with typical development, 13 children with known expressive morphosyntactic difficulties (specific language impairment), and two groups of 14 children with different types of speech disorder: a group with consistent phonological disorder, who used atypical phonological error patterns consistently; and a group with inconsistent phonological disorder, who produced atypical phonological errors inconsistently. Outcomes & Results: SIT-61 found differences in performance between the group of typically developing participants and the three clinic groups. While the consistent phonological disorder group obtained extremely high scores for content and function words, they obtained lower inflection scores reflective of their speech difficulties. The scores of the specific language impairment and inconsistent phonological disorder groups were comparable for content and function words, but the groups were differentiated through an analysis of their errors. Further analyses confirmed that low scores obtained by some children in the inconsistent phonological disorder group were due to morphosyntactic difficulties and not speech difficulties. Conclusions & Implications: A new sentence imitation test, the SIT-61, is shown to be valuable tool for identifying expressive morphosyntactic difficulties in children. It is informative about the morphosyntactic abilities of children with speech disorders and raises questions as to the nature of their difficulties

On the accuracy of the Perturbative Approach for Strong Lensing: Local Distortion for Pseudo-Elliptical Models

The Perturbative Approach (PA) introduced by \citet{alard07} provides analytic solutions for gravitational arcs by solving the lens equation linearized around the Einstein ring solution. This is a powerful method for lens inversion and simulations in that it can be used, in principle, for generic lens models. In this paper we aim to quantify the domain of validity of this method for three quantities derived from the linearized mapping: caustics, critical curves, and the deformation cross section (i.e. the arc cross section in the infinitesimal circular source approximation). We consider lens models with elliptical potentials, in particular the Singular Isothermal Elliptic Potential and Pseudo-Elliptical Navarro--Frenk--White models. We show that the PA is exact for this first model. For the second, we obtain constraints on the model parameter space (given by the potential ellipticity parameter $\varepsilon$ and characteristic convergence $\kappa_s$) such that the PA is accurate for the aforementioned quantities. In this process we obtain analytic expressions for several lensing functions, which are valid for the PA in general. The determination of this domain of validity could have significant implications for the use of the PA, but it still needs to be probed with extended sources.Comment: Accepted for publication in MNRA

Conspecific and allospecific larval extracts entice mosquitoes to lay eggs and may be used in attract-and-kill control strategy.

One of the strategies of integrated vector management is to lure gravid mosquitoes for surveillance purposes or to entice them to lay eggs in water containing toxins that kill the offspring (attract-and-kill or trap-and-kill). Typically, the major challenge of this approach is the development of a lure that stimulates oviposition plus a toxin with no deterrent effect. Bacillus thuringiensis var. israelensis (Bti) satisfies the latter criterion, but lures for these autocidal gravid traps are sorely needed. We observed that gravid Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus laid significantly more eggs in cups with extracts from 4th-stage larvae (4 L) of the same or different species. No activity was found when 4 L were extracted with hexane, diethyl ether, methanol, or butanol, but activity was observed with dimethyl sulfoxide extracts. Larval extracts contained both oviposition stimulant(s)/attractant(s) and deterrent(s), which partitioned in the water and hexane phases, respectively. Lyophilized larval extracts were active after a month, but activity was reduced by keeping the sample at 4 °C. In the tested range of 0.1 to 1 larvae-equivalent per milliliter, oviposition activity increased in a dose-dependent manner. In field experiments, Ae. aegpti laid significantly more eggs in traps loaded with larval extracts plus Bti than in control traps with water plus Bti

China’s Oil Security Pipe Dream—The Reality, and Strategic Consequences, of Seaborne Imports

It is widely believed in China that overland pipelines would greatly enhance the security of its oil supply. Market and geopolitical analysis, however, shows that they would not. Chinese decision makers must face the fact that, barring discovery of an economically viable large-scale substitute for crude oil, their nation’s dependence on seaborne oil imports will only increase

Putin’s Ukraine Invasion: Turbocharging Sino-Russian Collaboration in Energy, Maritime Security, and Beyond?

Putin’s war of choice in Ukraine will continue to send shock waves across the shores of maritime Asia for years, with unfolding impacts on ecosystems inhabited by oil barrels, gas pipelines, submarine technologies, jet engines, and basing access, within a context of a China-Russia relationship characterized over the centuries by cycles of fear, temporary bonds, and renewed division

No Oil for the Lamps of China?

Chinese naval and strategic planners fear, and their Western counterparts seem to believe, that a maritime blockade could interrupt or significantly impede China’s energy supplies in a limited war. But probably it could not, and thinking it could is dangerous for everyone

Theoretical determination of lifetimes of metastable states in Sc III and Y III

Lifetimes of the first two metastable states in Sc^{2+} and Y^{2+} are determined using the relativistic coupled-cluster theory. There is a considerable interest in studying the electron correlation effects in these ions as though their electronic configurations are similar to the neutral alkali atoms, their structures are very different from the latter. We have made a comparative study of the correlation trends between the above doubly ionized systems with their corresponding neutral and singly ionized iso-electronic systems. The lifetimes of the excited states of these ions are very important in the field of astrophysics, especially for the study of post-main sequence evolution of the cool giant stars.Comment: 13 pages, 1 figure and 5 table

Interdependent networks with correlated degrees of mutually dependent nodes

We study a problem of failure of two interdependent networks in the case of correlated degrees of mutually dependent nodes. We assume that both networks (A and B) have the same number of nodes $N$ connected by the bidirectional dependency links establishing a one-to-one correspondence between the nodes of the two networks in a such a way that the mutually dependent nodes have the same number of connectivity links, i.e. their degrees coincide. This implies that both networks have the same degree distribution $P(k)$. We call such networks correspondently coupled networks (CCN). We assume that the nodes in each network are randomly connected. We define the mutually connected clusters and the mutual giant component as in earlier works on randomly coupled interdependent networks and assume that only the nodes which belong to the mutual giant component remain functional. We assume that initially a $1-p$ fraction of nodes are randomly removed due to an attack or failure and find analytically, for an arbitrary $P(k)$, the fraction of nodes $\mu(p)$ which belong to the mutual giant component. We find that the system undergoes a percolation transition at certain fraction $p=p_c$ which is always smaller than the $p_c$ for randomly coupled networks with the same $P(k)$. We also find that the system undergoes a first order transition at $p_c>0$ if $P(k)$ has a finite second moment. For the case of scale free networks with $2<\lambda \leq 3$, the transition becomes a second order transition. Moreover, if $\lambda<3$ we find $p_c=0$ as in percolation of a single network. For $\lambda=3$ we find an exact analytical expression for $p_c>0$. Finally, we find that the robustness of CCN increases with the broadness of their degree distribution.Comment: 18 pages, 3 figure